Many homes, offices, apartments, and the like are heated and cooled by a forced air system. These systems generally include a central heating and cooling unit, such as a heat pump, duct work, registers and control units. These systems further include a filter, and air is circulated through such filter prior to entering the central heating and cooling unit for conditioning. The filtered and conditioned air is then sent to the various zones associated with the system.
As many are aware, homes, offices and the like are often subject to having odors permeate therethrough. These odors can be pleasant, such as cooking odors, or can be unpleasant, such as musty odors, or tobacco odors, or the like. Because there are certain odors which are unpleasant or are unwanted, the art contains numerous devices for eliminating such unwanted odors. These devices range from simple perfumes that are dispensed from a hand-held container to sophisticated ion exchange devices.
While such devices often work satisfactorily, they all have a common shortcoming in that they are quite localized. That is, these devices are room oriented and are effective in only small, local areas of an overall environment. Accordingly, if an entire environment is to be treated, several such devices will be required, one for each portion of the overall area.
These localized conditioners can be acceptable in some instances, but need to be replaced on a periodic basis and tend to produce zones that are more intensely treated than adjacent zones. Thus, for example, a kitchen may container a higher concentration of room deodorizer than an adjacent dinning room. In fact, these devices are so localized that there may be concentration gradients even within the same room. This may be wasteful and produce a noticeable change in scent within a room. The concept behind many of these devices is to produce a pleasant odor which becomes unnoticed except for a pleasant sensation. Unbalanced concentrations within a room defeats such object.
Since the central heating and cooling system can force air into all rooms and areas of a dwelling in equal or controlled amounts, the central heating and cooling system may be a good choice to distribute pleasant scents or germicidal gases throughout a dwelling.
Accordingly, there are several suggestions in the art for combining aromatic scent dispersing means with filters and the like that are used in a central forced air heating and cooling system. See, for example, the devices disclosed in U.S. Pat. Nos. 4,065,262, 4,563,333 and 4,604,114.
While effective in most situations, devices such as the above-mentioned patented devices, still have several drawbacks. For example, such devices, while used in conjunction with a filter for a central forced air system, still are quite localized within such filter, and thus may still produce concentration gradients. Still further, there is no sure way of determining when to replace such devices, and the entire device must be replaced if the scent is to be changed or if the scent of the device is exhausted. The amount of scent ingested into the air stream from such devices is also not totally controllable so that at certain times, such as at night, the same amount of scent is placed in the dwelling as at other times, such as during the day during cooking or at other high activity times. This is wasteful and may even be annoying as the amount of scent necessary to overcome high usage times may be overbearing at low use times.
Accordingly, there is a need for a means to supply a pleasing scent to an overall environment in a controllable, replenishable manner that will distribute scent in selected areas in an even, controlled manner.